The aim of the present work is to investigate the residual strength behavior of concrete reinforced with straight fibergalss fiber at levels of 0.8%, 1.2% and 1.6% and compare to hooked end steel fibers reinforced concrete same concentation. The laboratory tests were determined according to SP 297.1325800.2017 and reviewed literature. Test sampels was 100x100x400 with cut 17 mm in low beam in center. The residual strength behavior of Fiberglass reinforced concrete (FGRC) appeared to be comparable to SFRC, where the increase of fibers volume ratio cause the increase in prepeak and post-peak parameters of concrete. Nevertheless, the type of fibers influences much this dependency. Сoncrete mix composition was selected on the basis of compressive strength of control samples 37.5MPa. Tests were carried out to determine the crack resistance of fibre concrete on fibreglass fibre. Fibre F1 tested in this work showed a high result of extreme values of residual strength 36.3% higher than anchor fibre and 50% higher than corrugated fibre, this may be due to a more stable bond with the concrete matrix. The work resulted in concrete with crack resistance classes from Bft3= 2,5b to 6с. This study is a practical basis for the theoretical study of the effect of fibreglass fibre on the physical and mechanical characteristics of concrete.

Keywords: fiberglass fiber, FGRC, CMOD, pullout strength, analise, composite, residual strength